1. Field of the Invention
The present invention relates to a low-noise chain and a chain power transmission apparatus using the low-noise chain, and more particularly, to both roller and bushed type chains in which rollers do not collide with a bottom portion or surface of a sprocket, and also to a chain power transmission apparatus.
2. Prior Art
As shown in FIG. 15A conventional roller type and bushed type chains has rollers that collide with bottom portions or surfaces f between pairs of adjacent teeth e of a sprocket d as when the chain meshes with the sprocket. The rollers collide with the respective bottom portions at a right angle direction to a tangential line of the bottom portions as is clear from FIG. 15. Thus high impact noise is generated when collision between the roller or bush and the bottom portion occurs. Moreover, the higher the rotational speed of the sprocket is the greater is the collision speed between the roller or bush and the bottom portion and the subsequent impact noise. When this impact noise is continuously generated under high speed, it causes intermeshing noise having a constant frequency under a certain rotational speed of the sprocket.